Softening process for a cellulosic textile fabric and the softened fabric



United States Patent M 3,507,690 SOFTENING PROCESS FOR A CELLULOSIC TEXTILE FABRIC AND THE SOFIENED FABRIC George B. Walker, Mariemont, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio No Drawing. Filed May 24, 1967, Ser. No. 640,843 Int. Cl. D06m 13/46 US. Cl. 117-1395 7 Claims ABSTRACT OF THE DISCLOSURE A process for softening water absorbent cotton fabric by depositing thereon from about .5 to about of a quaternary ammonium compound of the formula on Z1 on Z3 on 1 l g l 1 n-orrcnm CH2 HCHzN onion-R Z2 x z x wherein R is an alkyl radical containing from about 1-0 to about 14 carbon atoms, and from 0 to about 2 ether linkages, each ether linkage counting as one carbon atom; Z Z Z and Z are methyl, ethyl, or hydroxyethyl radicals; and X is chloride, bromide, or iodide.

Background of the invention Various cationic nitrogenous compounds with a hydrophobic group in their structure have been used with success as textile finishing agents to impart a soft feel to cellulosic textile fabrics. Treatment of water absorbent cellulosic textile fabrics with such compounds, however, generally tends to make cellulosic textile fabrics much less Water absorbent, and' in some cases, Water absorbent cellulosic textile fabrics are rendered water repellent by treatment with such cationic nitrogen compounds.

In home laundry use, these cationic nitrogenous fabric softening compounds are generally employed in such low concentrations that problems with water absorbency are not encountered until after several treatments. After several treatments, however, there is a buildup of these fabric softening compounds on the fabric, and water absorbency can be decreased. This problem is encountered more immediately in industrial applications where it is the general practice to impart the desired degree of softness to a fabric by treating the fabric in a one-step application with a high concentration of fabric softener; for example, where from about .5% to about 5%, based on the weight of the fabric, of fabric softener is deposited on the fabric. In such processes, the water absorbency of the treated fabric is often reduced immediately.

Loss of water absorbency in a cellulosic textile fabric is often objectionable for water absorbent textile fabrics are desirable in many applications; for example, it is especially desirable that towels and diapers be fashioned from water absorbent textile fabrics. While it is desirable that these textile products be water absorbent, it is also often desirable that such products, and other products fashioned from water absorbent cellulosic textile fabrics, have a soft feel.

Summary of the invention This invention involves the treatment of water absorbent cellulosic textile fabrics with high levels of certain very specific cationic nitrogenous compounds which unexpectedly give a cellulosic textile material which is highly softened and yet retains a large measure of its original water absorbency. These specific cationic nitrogen 3,507,690 Patented Apr. 21, 1970 wherein R is an alkyl radical containing from about 10 to about 14 carbon atoms, and from 0 to about 2 ether linkages, each ether linkage counting as one carbon atom; Z Z Z and Z are each selected from the group consisting of methyl, ethyl and hydroxyethyl radicals; and X is a halide selected from the group consisting of chloride, bromide, and iodide. While these specific cationic nitrogenous compounds are useful in home laundry applications, they find especial utility in industrial processes where the practice is to deposit large amounts of fabric softener on the fabric in a one-step application.

As a more specific summary, this invention provides a softened water absorbent cellulosic textile fabric having deposited thereon from about .5 to about 5% of these cationic nitrogenous compounds, and a process for softening water absorbent cellulosic textile fabrics comprising (I) forming an aqueous solution consisting essentially of from about 0.5% to about 5% of quaternary ammonium compounds selected from the group of compounds of the formula OH z on 011 1 I I I I R- HCHzN omoHomN onion-R Z x 2' R wherein R is an alkyl radical containing from about 10 to about 14 carbon atoms, and from about 0 to about 2 ether linkages, each ether linkage counting as one carbon atom; Z Z Z and Z are each selected from the group consisting of methyl, ethyl, and hydroxyethyl radicals; and X is a halide selected from the group consisting of chloride, bromide, and iodide; (II) padding cellulosic textile fabric with said aqueous solution, the weight of said aqueous solution being retained on said fabric being such that from about .5 to about 5 based on the weight of said fabric, of said quaternary ammonium compounds is deposited on said fabric after drying; and (III) drying said textile fabric.

Discussion of the invention and its preferred embodiments The specific cationic nitrogen compounds useful in this invention are quaternary ammonium compounds of the formula wherein R is an alkyl radical containing from about 10 to about 14 carbon atoms, and from 0 to about 2 ether linkages, each ether linkage counting as one carbon atom; Z Z Z and Z are selected from the group consisting of methyl, ethyl, and hydroxyethyl radicals; and X is a halide selected from the group consisting of chloride, bromide, and iodide. Of the above-mentioned compounds, preferred are those wherein the radical R is selected from the group consisting of tetradecyl (C H octoxymethyl (C H OCH decoxymethyl (C H OCH dodecoxymethyl (C H OCH and the halide X is selected from the group consisting of chloride and bromide.

Treatment of cellulosic textile fabrics with the abovementioned quaternary ammonium compounds comprises essentially (I) forming an aqueous solution of said quaternary ammonium compounds by mixing said compounds With water, (II) padding the cellulosic textile fabric with said aqueous solution, and (III) drying the cellulosic teX- tile material padded with said solution, such that from about .5% to about preferably from about .7% to about 4%, based on the weight of the fabric of the quaternary ammonium compound is left deposited on the fabric.

Most preferably, the treatment of a cellulosic textile fabric comprises (I) forming an aqueous solution consisting essentially of from about 0.5% to about 5% of the above-mentioned quarternary ammonium compounds by mixing said quarternary ammonium compounds with Water, (II) padding the cellulosic textile fabric with said aqueous solution, the weight of said aqueous solution being retained on the textile fabric being from about 50% to about 100% based on the weight of said fabric, such that from about .7% to about 4%, based on the weight of said fabric, of said quaternary ammonium compounds is deposited on said fabric after drying, and (III) drying said textile fabric.

In practice, the cellulosic textile fabric to be treated is generally immersed in, or sprayed with, the aqueous solution of the quaternary ammonium compounds in accordance with conventional padding operations. Preferably, padding is accomplished by immersing the cellulosic textile material in the aqueous solution of the quaternary ammonium compound. If the fabric is immersed in the aqueous solution, it may pick up more of the aqueous solution than is desirable. This excess solution can be conveniently removed by squeezing the excess solution from the material. Preferably this squeezing is accomplished by a wringer or squeeze rollers.

In order that the amount of the quaternary ammonium compounds picked up and retained on the fabric will be sufficient to give a marked softening effect in one application, the aqueous solution preferably contains at least 0.5 by weight of the quaternary ammonium compounds. Aqueous solutions containing more than about 5% by weight of the quarternary ammonium compounds, hoW- ever, are not generally desirable for so much of the quaternary ammonium compound can be picked up by the fabric that it is not easily removed.

The temperature of the aqueous solution of the quaternary ammonium compounds in the process is not critical; a temperature of from about 20 C. to about 80 C. is satisfactory.

The wet fabric which has been padded with an aqueous solution of quaternary ammonium compounds in accord ance with the preferred process hereinbefore described holds from about 50% to about 100%, based on the weight of the fabric, of the aqueous solution. When this fabric is dried, preferably in a stream of hot air, there is left deposited on the fabric the quarternary ammonium compound which was in solution. The temperature of this stream of hot air is critical, but is should be such that the treated fabric is dried promptly. Preferably the temperature is from about 20 C. to about 60 C. The method of drying the treated cotton fabric is not critical, and any other suitable method can be used.

The cellulosic textile fabric resulting from this process is a new cellulosic textile fabric which has deposited on it from about .5% to about 5%, preferably from about .7% to about 4%, based on the weight of the fabric, of the quaternary ammonium compounds of this invention. This novel cellulosic textile fabric is highly softened and retains a large measure of its original water absorbency.

The water absorbent cellulosic textile fabrics which are particularly useful in the process of this invention are water absorbent fabrics prepared principally from cotton and rayon, cotton fabric being especially preferred.

The quaternary ammonium compounds useful in this invention can be obtained by several methods known to those skilled in the art. US. Patent 2,113,606 in Example 7 discloses the preparation of one of the preferred compounds of this invention, tetramethyl di (dodecyloxy ,8 hydroxy-propyl) a hydroxy-propylene-diammonium chloride, i.e.,

m on. c n :11. n: 01.11250 c1no1-ronmomononmonionolno (1121125 on. 01 on3 01 Methods of preparation analogous to those disclosed therein can be used to prepare the structurally analogous compounds useful in the process of this invention.

Quaternary ammonium compounds, useful in this invention, which have no ether linkages in the alkyl group are preferably prepared in the following fashion. A suitable olefin oxide is prepared by reacting peracetic acid with a suitable alpha olefin according to Equation 1,

R1CH=OH2 OHzCOOOH R CL I GNz CHQCOOH (Equation 1) This olefin oxide can be reacted with di methylamine at from about 50 to about 200 p.s.i.g. and from about 200 C. to about 300 C. to give a tertiary amine according to Equation 2,

CH3 R -Cfi CH2 HN/ "(Equation 2) This tertiary amine can be reacted with a 1,3-dihalo-2- propanol under alkaline conditions, for example in the presence of NaOH, at a temperature of from about 25 C.

-- n -on-onm (Equation 3) (In the above Equations 1-3, R can be an alkyl group containing from about 10 to 14 carbon atoms, and X is selected from the group consisting of chloride, bromide, and iodide.) Other methods for preparing the cationic nitrogen compounds useful in the process of this invention are known and taught in the prior art.

The following examples describe with particularity several of the preferred embodiments of the invention described hereinbefore. It will be obvious to those skilled in the art that the invention can be performed in numerous other ways. These examples are, therefore, given by way of additional illustration and not by way of limitation.

Example 1 This example indicates the nature of the improvement obtained in the process of this invention. Two lengths of crash towelling, a water absorbent cotton fabric, were treated in the following fashion. One length of the fabric was padded with a 1% aqueous solution of a commercial softener Arquad 2HT, a widely-used fabric softener. (The trade name Arquad ZHT designates the cationic quaternary ammonium compound di[hydrogenated tallow] dimethyl ammonium chloride.) Padding was accomplished by dipping the fabric into the abovementioned aqueous solution of the compound. The amount of the aqueous solution picked up by the towelling Was adjusted to 70% of the weight of the fabric by wringing out the excess solution with squeeze rollers. The fabric was then dried by means of a stream of hot air having a temperature of 50 C. After drying, .7 based on the weight of the fabric, of the softener Arquad 2HT remained deposited on the fabric. The other length of crash towelling was treated in the same manner except that the cationic ammonium compound used was one selected from the class taught for use in this invention, specifically the compound tetramethyl di (dodecyloxy B hydroxy propyl) flhydroxy-propylene-diammonium chloride. For convenience, this compound is designated AB.

Strips 1" by 9" were cut from each of the lengths of towelling so treated. These strips were conditioned for 8 hours at 70 F. and 65% relative humidity.

The strips of fabric were equally softened. Therefore, the softener Arquad 2HT and softener AB have similar softening activity.

That softener AB is markedly superior to the softener Arquad 2HT regarding its effect on the water absorbency of treated cotton fabric is shown by the following wicking test.

The wicking test is performed by immersing one end of the above-mentioned treated and conditioned cotton strips in a trough of distilled water colored with methylene blue to a depth of one inch. The test strips absorb water as denoted by the spreading of the blue dyed water line. For control purposes a 1" by 8"strip of crash towelling not treated with a fabric softener but conditioned as above, was also used. The results are as follows:

CENTIMETERS RISE ON 1" x 9" PIECE OF FABRIC Arquad Control 2H'l. AB

centimeters rise in 2 minutes 8. 4 0. 5 5. 1 Centimeters rise in 5 minutes l1. 2 1.0 9. 1

In the same manner, a test was conducted using terry cloth, a cotton fabric. The results are as follows:

CENTIMETERS RISE ON 1" X 9" PIECE OF FABRIC Control Centimeters rise in 2 minutes 9. 5 5. 8 Centimeters rise in minutes 14. 4 0 8. 5

Example 2 Terry cloth, a botton fabric, was padded with a 2% aqueous solution of tetramethyl-di-(,B-hydroxy-hexadecyl)-fl-hydroxy-propylene-diammonium chloride, i.e.

The amount of the aqueous solution picked up by the terry cloth was adjusted to 70% of the weight of the cloth by squeezing excess solution from the cloth with squeeze rollers. The cloth was then dried by a stream of hot air having a temperature of 50 C. The resulting terry cloth product was measurably softened and retained a large measure of its original water absorbency.

Example 3 When, in Example 2, the following quaternary ammonium compounds are substituted for tetramethyl-di-(B- hydroxy hexadecyl) B hydroxy propylene diammonium chloride, substantially the same results can be obtained, in that the cloth is softened while retaining a large measure of its original water absorbency:

(l tetramethyl-di-(octoxy-B-hydroxy-propyl) -[1- hydroxy-propylene-diarnonium chloride;

(2 tetramethyl-di- (decoxy-fi-hydroxy-propyl) -/3- hydroxy-propylene-diamonium chloride;

(3 tetramethyl-di-(fl-hydroxy-dodecyl) -p-hydroxypropylene-diammonium chloride;

(4) tetramethyl-di-(fl-hydroxy-tetradecyl)-B-hydroxypropylene-diammonium chloride;

(5 tetrarnethyl-di-(decoxy-B-hydroxy-propyl) 8- hydroxy-propylene-diammonium bromide;

( 6 tetramethyl-di- (,B-hydroxy-dodecyl) -;8-hydroxypropylene-diammonium iodide;

(7 tetraethyl-di- (octoxy-fl-hydroxy-propyl) -5- hydroxy-propylene-diamonium chloride;

(8 tetraethyl-di- (dodecyloxy-fl-hydroxy-propyl) -B- hydroxy-propylene-diamonium chloride;

(9 tetrahydroxyethyl-di- (fi-hydroxy-tetradecyl) 13- hyroxy-propylene-diammonium bromide;

( 10) tetrahydroxyethyl-di- (octoxy-fi-hydroxy-propyl p-hydroxy-propylene-diammonium bromide.

Example 4 Rayon cloth, a cellulosic textile fabric, is padded with a 3% aqueous solution of tetramethyl-di-(pi-hydroxyhexadecyl) 8-hydroxy-propylene diammonium chloride, i.e.

The amount of the aqueous solution picked up by the rayon cloth is adjusted to 50% of the weight of the cloth by squeezing excess solution from the cloth with squeeze rollers. The cloth is then dried by a stream of hot air having a temperature of 40 C. The resulting rayon cloth product is measurably softened and retains a large measure of its original water absorbency.

What is claimed is:

1. A process for softening water absorbent cellulosic textile fabrics comprising:

(I) forming an aqueous solution consisting essentially of from about 0.5% to about 5% of quaternary ammonium compounds selected from the group of compounds of the formula wherein R is an alkyl radical containing from about 10 to about 14 carbon atoms, and from about 0 to about 2 ether linkages, each ether linkage counting as one carbon atom; Z Z Z and Z are each selected from the group consisting of methyl, ethyl, and hydroxyethyl radicals; and X is a halide selected from the group consisting of chloride, bromide, and iodide;

(II) padding cellulosic textile fabric with said aqueous solution, the weight of said aqueous solution being retained on said fabric being such that from about .5 to about 5%, based on the weight of said fabric, of said quaternary ammonium compounds is deposited on said fabric after drying; and

(HI) drying said textile fabric.

2. The process of claim 1 wherein the cellulosic textile fabric is cotton fabric.

3. The process of claim 1 wherein from about .7% to about 4% of said quaternary ammonium compounds are deposited on the cellulosic textile fabric.

4. The process of claim 1 wherein R is an alkyl radical selected from the group consisting of decyl, dodecyl, tetradecyl, octoxymethyl, decoxymethyl, and dodecoxymethyl.

5. A softened water absorbent cellulosic textile fabric product having a deposited thereon from about .5 to about 5% based on the weight of the fabric of a quaternary ammonium compound selected from the group of compounds of the formula wherein R is an alkyl radical containing from about 10 to about 14 carbon atoms, and from about 0 to about 2 ether linkages, each ether linkage counting as one carbon atom; Z Z Z and Z are each selected from the group consisting of methyl, ethyl, and hydroxyethyl radicals; and X is a halide selected from the group consisting of chloride, bromide, and iodide.

6. The product of claim 5 wherein the cellulosic textile fabric is cotton.

7. The product of claim 5 wherein the cellulosis textile fabric is cotton having deposited thereon from about .7%

to about 4%. based on .the weight of the fabric of a quaternary ammonium compound selected from the group of compounds of the formula References Cited UNITED STATES PATENTS 4/1938 Taub et al 260567.6 5/1967 Curtin 260567.6

MURRAY KATZ, Primary Examiner T. G. DAVIS, Assistant Examiner US. Cl. X.R. 

